This invention relates generally to a film reader and, more particularly, it relates to a film reader which has a projector enclosed in a housing to project at least a portion of a film on the screen, and a film holder which is supported on a slide carriage which in turn is supported on a transverse slide carriage for movement in the illumination plane of the projector.
In conventional film readers of this type the operator directly displaces the film holder in two directions in order to place the desired film portion to be projected in front of the objective in the film reader. Such direct actuation of the film holder, however, has the disadvantage that a fine position adjustment of the film is difficult especially in the case when the film is a microfilm, the projected portions of which are very small and require a considerable magnification. Another disadvantage of the known film readers having a projector located laterally to the screen is in the fact that the film has to be shifted in an opposite direction than that which is desired on the screen. This condition has the consequence that in practice even experienced operators frequently make errors in the correct positioning of the projected image resulting in time losses.